Guideline directed medical therapy and reduction of secondary mitral regurgitation

Background: Guideline-directed medical therapy (GDMT) is the recommended initial treatment for secondary mitral regurgitation (SMR), however, supported by only little comprehensive evidence. This study, therefore, sought to assess the effect of GDMT titration on SMR and to identify specific substance combinations able to reduce SMR severity.

Methods and results: We included 261 patients who completed two visits with an echocardiographic exam available within 1 month at each visit. After comprehensively defining GDMT titration as well as SMR reduction, logistic regression analysis was applied in order to assess the effects of overall GDMT titration and specific substance combinations on SMR severity. SMR severity improved by at least 1° in 39.3% of patients with subsequent titration of GDMT and was accompanied by reverse remodelling and clinical improvement. The effects of GDMT titration were significantly associated with SMR reduction (adj. odds ratio 2.91, 95% confidence interval 1.34-6.32, P = 0.007). Moreover, angiotensin receptor/neprilysin inhibitor (ARNi) as well as the combined dosage effects of (i) renin-angiotensin system inhibitors (RASi) and mineralocorticoid-receptor antagonists (MRA), (ii) beta-blockers (BB) and MRA, as well as (iii) RASi, BB, and MRA were all significantly associated with SMR improvement (P < 0.044 for all).

Conclusion: The present study provides comprehensive evidence for the effectiveness of contemporary GDMT to specifically improve SMR. Our data indicate that GDMT titration conveys a three-fold increased chance of reducing SMR severity. Moreover, the dosage effects of ARNi, as well as the combination of RASi and MRA, BB and MRA, and all three substances in the aggregate are able to significantly improve SMR.